#include<iostream>
#include <vector>
using namespace std;
class Solution {
public:
    int uniquePathsWithObstacles(vector<vector<int>>& obstacleGrid) {
        int n = obstacleGrid.size();
        int m = obstacleGrid[0].size();
        if (obstacleGrid[0][0] == 1 || obstacleGrid[n - 1][m - 1] == 1)return 0;
        vector<vector<int>>dp(n, vector<int>(m, 0));
        dp[0][0] = 1;
        for (int i = 1; i < n; i++) {
            if (obstacleGrid[i][0] == 0) {
                dp[i][0] = dp[i - 1][0];
            }
            else {
                dp[i][0] = 0;
            }
        }
        for (int i = 1; i < m; i++) {
            if (obstacleGrid[0][i] == 0) {
                dp[0][i] = dp[0][i-1];
            }
            else {
                dp[0][i] = 0;
            }
        }
        for (int i = 1; i < n; i++) {
            for (int j = 1; j < m; j++) {
                if (obstacleGrid[i][j] == 0) {
                    dp[i][j] = dp[i - 1][j] + dp[i][j - 1];
                }
                else {
                    dp[i][j] = 0;
                }
            }
        }
        return dp[n - 1][m - 1];
    }
};